stm32wl: Do not require external SPI pins for SUBGHZ

For the Seeed Studio Lora-E5 those pins conflict with the radio frontend control GPIOS (PA4 and PA5).

embassy-stm32/src/spi/mod.rs

@@ -179,6 +179,18 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
         )
     }
 
+    /// Useful for on chip peripherals like SUBGHZ which are hardwired.
+    /// The bus can optionally be exposed externally with `Spi::new()` still.
+    pub fn new_internal(
+        peri: impl Peripheral<P = T> + 'd,
+        txdma: impl Peripheral<P = Tx> + 'd,
+        rxdma: impl Peripheral<P = Rx> + 'd,
+        freq: Hertz,
+        config: Config,
+    ) -> Self {
+        Self::new_inner(peri, None, None, None, txdma, rxdma, freq, config)
+    }
+
     fn new_inner(
         peri: impl Peripheral<P = T> + 'd,
         sck: Option<PeripheralRef<'d, AnyPin>>,

embassy-stm32/src/subghz/mod.rs

@@ -81,7 +81,7 @@ pub use value_error::ValueError;
 use crate::dma::NoDma;
 use crate::peripherals::SUBGHZSPI;
 use crate::rcc::sealed::RccPeripheral;
-use crate::spi::{BitOrder, Config as SpiConfig, MisoPin, MosiPin, SckPin, Spi, MODE_0};
+use crate::spi::{BitOrder, Config as SpiConfig, Spi, MODE_0};
 use crate::time::Hertz;
 use crate::{pac, Peripheral};
 
@@ -212,9 +212,6 @@ impl<'d, Tx, Rx> SubGhz<'d, Tx, Rx> {
     /// clock.
     pub fn new(
         peri: impl Peripheral<P = SUBGHZSPI> + 'd,
-        sck: impl Peripheral<P = impl SckPin<SUBGHZSPI>> + 'd,
-        mosi: impl Peripheral<P = impl MosiPin<SUBGHZSPI>> + 'd,
-        miso: impl Peripheral<P = impl MisoPin<SUBGHZSPI>> + 'd,
         txdma: impl Peripheral<P = Tx> + 'd,
         rxdma: impl Peripheral<P = Rx> + 'd,
     ) -> Self {
@@ -227,7 +224,7 @@ impl<'d, Tx, Rx> SubGhz<'d, Tx, Rx> {
         let mut config = SpiConfig::default();
         config.mode = MODE_0;
         config.bit_order = BitOrder::MsbFirst;
-        let spi = Spi::new(peri, sck, mosi, miso, txdma, rxdma, clk, config);
+        let spi = Spi::new_internal(peri, txdma, rxdma, clk, config);
 
         unsafe { wakeup() };
 

examples/stm32wl/src/bin/lorawan.rs

@@ -31,7 +31,7 @@ async fn main(_spawner: Spawner) {
     let ctrl3 = Output::new(p.PC5.degrade(), Level::High, Speed::High);
     let rfs = RadioSwitch::new(ctrl1, ctrl2, ctrl3);
 
-    let radio = SubGhz::new(p.SUBGHZSPI, p.PA5, p.PA7, p.PA6, NoDma, NoDma);
+    let radio = SubGhz::new(p.SUBGHZSPI, NoDma, NoDma);
 
     let irq = interrupt::take!(SUBGHZ_RADIO);
     static mut RADIO_STATE: SubGhzState<'static> = SubGhzState::new();

examples/stm32wl/src/bin/subghz.rs

@@ -72,7 +72,7 @@ async fn main(_spawner: Spawner) {
         unsafe { interrupt::SUBGHZ_RADIO::steal() }.disable();
     });
 
-    let mut radio = SubGhz::new(p.SUBGHZSPI, p.PA5, p.PA7, p.PA6, NoDma, NoDma);
+    let mut radio = SubGhz::new(p.SUBGHZSPI, NoDma, NoDma);
 
     defmt::info!("Radio ready for use");